1. Field of the Invention
This invention relates to an exposure ascertaining device for cameras.
2. Description of the Prior Art
A conventional camera is not provided with a means for making sure that a film has been exposed without trouble in a photographing operation.
Conventional cameras include a camera in which sequential photographing actions are made by mechanical interlocking actions. In a case where even one movable member of such type of camera among a plurality of movable members thereof, which are moved when a film is exposed, has got out of order to be stopped, other movable members operatively connected to the first-mentioned movable member also come to a stop. This causes a shutter to become inoperable at last. In many cases, an accident to such a camera comes under the user's notice only when a shutter trouble as mentioned above occurs. In addition, it would occur that a shutter trouble, in which a shutter is stopped in an opened state, is left unnoticed to result in a loss of an opportunity of taking photographs and wasteful consumption of a film.
Conventional cameras also include a camera in which sequential photographing actions are made by an electric control circuit. In such type of camera, operational instructions are given to each movable member thereof by the control circuit in accordance with sequential photographing actions to thereby move the members. Therefore, even in a case where one of these members gets out of order to be stopped when a film is exposed, the other members are moved normally. Such a trouble would not come under the user's notice until the film has been developed.